Concord River - Effects of Pollution

Effects of Pollution

During the 19th century, the Concord River was near the heart of the US Industrial Revolution. Textile, paper, tanning, and mining industries all emerged during this period. Massive amounts of waste were dumped directly into the river, which was already heavily laden with untreated sewage and other organic waste. Industrial development within the watershed peaked in the 1920s. However, in the early 1960s, manufacturing was again on the rise, along with chemical and metal firms in support of the electronics industry within the Boston metropolitan area. By the 1960s, the Merrimack River was considered one of the top ten most polluted waterways in America. Factories located along the Concord River contributed to this situation because the river flows directly into the Merrimack.

The passage of the Clean Water Act in 1972 signaled the beginning of US efforts to improve the quality of its waterways. The act imposed stricter controls on point source discharges into rivers and other navigable waters. This eventually led to the installation of three wastewater treatment plants on the banks of the Concord River: one in Concord and two in Billerica. These plants have helped to prevent subsequent damage to the river ecosystem when they were able to operate within federally mandated limits.

Unfortunately, many pollutants, such as heavy metals and PCBs, remain trapped in the sediment. Throughout much of the Sudbury River downstream into the Concord River, fish consumption is banned due to mercury-laden sediments from the Nyanza Superfund site and other sources.

Perchlorate was also detected in the Concord River in August 2004. Initially, it was believed that explosives used in road and building construction were the source of this pollutant. However, an investigation by the town of Billerica eventually determined that the source was a local company that produced surgical and medical materials. The company was using 220 gallons per month of perchloric acid in a bleaching process, and rinse water was being discharged into the sewage system. After the company was identified, it voluntarily shut down until ion exchange equipment could be installed in accordance with environmental guidelines.

In May 2007, Billerica was again in the news when the town itself was the subject of legal action. The town was forced to pay a $250,000 penalty for discharging pollutants into the Concord River. The action was brought by the U.S. Environmental Protection Agency (EPA) and the Massachusetts Department of Environmental Protection (MassDEP) because the town of Billerica exceeded allowable effluent limits for phosphorus, fecal coliform bacteria, pH, and ammonia nitrogen. The town was also charged with failing to submit discharge monitoring reports, failing to comply with monitoring requirements, and failing to submit infiltration and inflow reporting. According to the EPA, Billerica's discharges of phosphorus created an overabundance of nutrients, which damaged the river by stimulating excessive aquatic plant growth.